Cement



COATING R PLASTIC.

8 4 Patented Sept. 18, 1934 1,973,732

UNITED STATES PATENT OFFICE CEMENT Foster Dee Snell, Brooklyn. N. Y.

No Drawing. Application January 9, 1932, Serial No. 585,805

6 Claims. (01. 106-30) The present invention has for an object to prois improved in practical use by having excess vide an improved cement. sodium fluo-silicate present.

The invention has been developed in connection A satisfactory dry acid-proof cement may be with the production of an id roof ceme t of made in accordance with the formula: a type suitable for use in the construction of Parts masonry that must withstand exposure to acid Aggregate 100 or acid fumes, and, for convenience of disclosure sodium 'g to such an embodiment of the invention will be desodium flumsilicate 1 to 25 scribed to illustrate the principles involved, but 9 it will be understood that the particular descrip- An optimum composition probably approxition is not intended as defining the limits of the t invention and that the principles of the invention Part can be extended to the production of cements of A e 100 other character and useful for other purposes. s'firm gncate 25 15 Cements of this type as previously used hav W nmuO-SllCate 23 consisted of a powder of acid resisting material such as ground stoneware or other suitable ag- The sodium silicate preferably used is that gregate andsodimn siiioate solution with hi h known as G. C. Brand silicate. It is a solid siliit was mixed iust prior to use. Cements have a e containing 27.5% sodium oxide and $111- 20 also been sold in liiiuid ofplastic form consistin con dioxide. It therefore has the ratio of 1:2.

of an aggregate or grog mixed with g, diu The balance of 17.5% issubstantially all water. silicate solution and stored in air-tight contain- The method o m ac co sts simp y of em. suitably grinding and then thoroughly mixing the One of the objects of the present invention is ingredients- 1158 QQXPQW-TER be 25 t provide ement h h may b produced and thoroughly mixed with suflicient water to insure supplied in powdered form having such ingresolution of the soluble ingredients. It is advandients that it may be mixed with water for use tflgeous to use Water a temperature 0! about in the same way as ordinary cement, 013 to Obtain better solution of the dry ma- Another object is to provide a cement of this 30 character which will be uid prqqf when t, In the above formula if the sodium silicate is Another obieEtis to'provide a cement of this one having a ratio f 1 Par sodium oxide to 2 character which will b re ista t t w t parts silicon dioxide then 100% of the sodium 1 have found that a mixture f round stoneoxide will be neutralized when the dry cement T' is suitably mixed with water and some excess e or ot ro with a soluble ow ered so- 5W 5 ma e W Se when mlxe wit wa er u sodium fluo-silicate will be present. on y par la y and after a considerabfm en of The cement produced as above indicated retime If, however 8 mteria1 is present in the mains workable for approximately an hour after mixin with water and et it will set com letel .gi fi n a mmh within 24 hours. y p y 40 ti fifiiwgifi lg ifai glnm' Tests on two inch cubes of material made in mm 5 Comp 9 e Se mg w a accordance with this formula and aged for three s or weeks have shown an average crushing strength w uo-silicate effective for this pymgfi of fifteen hunderd pounds per square inch, and 8 p esence m e nilxiul'e f 811011811 SOdmm dumb-bell pieces of one inch sectional area after fiuo-silicate to neutralize from 50% to 100% of i ilar aging showed a tensile strength of 385 the sodium oxigdg of the silicate will give a satispounds, f c H iglste ngu ga iee iqgg is fl van- The contraction of the two inch cubes appears tageous, however, since in that case a cement is to be less than 1/64 of an inch on a side during the produced which is resistant to the dissolving acfirst 24 to 48 hours. 50 tion of water, as well as resistant to acid. This It is a feature of this cement that it is water proof especially if an excess amount of sodium fluo-silieate is used. Any reduction in the amount of sodium duo-silicate will cause a slight disintegration of the final product in cold water.

This cement has the advantage that it is not necessary to paint the cement with sulphuric acid previous to use of the equipment.

In order to determine the resistance to acids and water, cubes of the cement were immersed in concentrated sulphuric, concentrated hydrochloric, concentrated acetic and concentrated nitric acids and in water. Each was brought to a boiling point once each day for six days. At the end of that time the cubes were washed thoroughly and again dried to constant weight in vacuo. The losses of weight caused by these reagents were as follows:-

Concentrated sulphuric acid Gain in weight Concentrated hydrochloric acid 4.89% Concentrated acetic acid 3.88% Concentrated nitric acid 3.54% Water 6.91%

These losses in weight correspond to minor amounts of soluble ingredients present in the original cement. There was no further loss in weight with additional treatment. Similarly cubes were tested to determine the effect of weak alkali and the loss after six days with heating to boiling once each day was found to be on the average 5.39%.

Certain advantages may be obtained if acid wis substituted for a portion of the sodium ate. The substitution may be for example, of the proportion of 17 pounds of sodium fluo-silicate and four pounds of sodium acid uon e o replace 23 to 28 poun s 0 so lum uo-s icate. It will be noted that the sodium fluo-silicate is reduced by more than the weight of the acid fluoride added.

A satisfactory dry acid proof cement containing acid fluoride may be made in accordance with the formula:

Parts Aggregate 100 Sodium silicate 20 to 30 Sodium fiuo-silicate 10 to 20 Sodium acid fluoride l to '7 An optimum composition probably approxi- The ingredients should be ground fine and thoroughly mixed. It is found convenient and effective to grind together the fluo-silicate and the acid fluoride with a portion of the aggregate of approximately equivalent weight.

It will be understood that the foregoing description of a particular embodiment of the invention developed for use as an acid proof cement is illustrative merely and variations in the composition may be developed when the cement is to be applied to other uses such for example as a binder for abrasive wheels or for artificial limestone or patching material for cement floors without departing from the spirit of the invention as defined in the claims.

I claim:

1. An acid proof cement comprising a combination in substantially the proportions indicated:

Parts Aggregate 100 Sodium silicate (1:2 ratio) 25 Sodium fluo-silicate 23 said materials reacting when mixed with water to provide a workable cement which acts to form an acid proof and water proof product substantially as described.

2. An acid proof cement comprising a combination in substantially the proportions indica ed:

Parts Aggregate 100 Sodium silicate 25 Sodium fluo-silicate 19 Sodium acid fluoride 5 3. A cement composition capable of setting to an acid proof and water proof product comprising a dry mixture of ground aggregate, a readily soluble powdered sodium silicate and sodium fluosilicate in a proportion which completely neutralizes the sodium oxide of the silicate, m silicate mixture being completely soluble in water and capable of being applied before setting commences.

4. A cement comprising a dry mixture of ground aggregate powdered sodium silicate of NazOzsioz ratio of 1 to 2, and sodium fluosilicate in a proportion which completely neutralizes the sodium oxide of the silicate, said mixture being capable of setting to an acid proof and water proof product.

5. A dry cement composition comprising ground aggregate, powdered sodium silicate, powdered sodium fluo-silicate and a small amount of sodium acid fluoride.

6. A dry finely ground cement composition comprising aggregate, sodium silicate of Na2O:SiO2 ratio of 1 to 2, sodium fluosilicate and a small quantity of sodium acid fluoride.

FOSTER DEE SNELL. 

